Behavioral red flags

Last updated: 2015-07-30
Document type: Information Sheet
Topic: Behavior and Enrichment
Species: Canine, Feline

Learn to recognize and alleviate mental distress in shelter animals before it leads to unwanted, even dangerous behavior. Includes photos of some behavioral red flags.

Animals displaying signs of marked mental distress, such as those listed below, require immediate action to relieve distress and in some cases avoid physical harm to that animal or others. Actions to correct these conditions will depend on the individual circumstance and could include moving the animal to another, quieter housing area; providing a larger cage or enclosure; moving the animal to individual housing if it was group-housed or vice versa; providing a hiding place, bed or other comfort and concealment; or in the case of stereotypic behaviors, removal to a more enriched environment such as a staff office or foster home.

If modification of the environment (in combination with behavioral modification +/- drug treatment if appropriate) does not alleviate clinical signs of severe behavioral distress within a reasonable time period, then transfer to another organization, release to the field if safe/appropriate, or humane euthanasia should be considered.

Signs of behavioral distress:

  • Trembling/shaking
  • Frozen or tense/stiff body posture or cowering into corners/gutters etc. for more than 1 hour


  • Pressing or facing into the corner of the enclosure 


  • Constant or frequent growling, hissing, or lunging at the front of the cage
  • Failure to eat for more than 24 hours, with medical causes ruled out
  • Efforts to escape to the point of self-injury, e.g. blood on mouth or paws from chewing or clawing to escape
  • Severely messing up or destroying cage (e.g. overturned litterbox, food or water dishes; feces and urine smeared everywhere)


  • Eliminating outside the litter box within the shelter environment (as opposed to history of inappropriate elimination)
  • Stereotypic behaviors such as repetitive pacing, spinning or lunging
  • For group housed animals (including littermates and “bonded pairs”)
    • Food guarding or inability to access guarded food within the enclosure
    • Attacking or being attacking by another animal within the enclosure

To read about how to address many of these issues and meet animals behavioral needs, see our info sheet on enrichment recommendations for dogs and cats in shelters.

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